Zombie Research Society
Euclid of Alexandria is most famously quoted as saying that “The laws of nature are but the mathematical thoughts of God.” But when we apply this concept to epidemiology, infectious diseases, and the inevitable zombie apocalypse, another quote comes to mind; “When there’s no more room in hell, the dead will walk the earth.” It’s unlikely that our friend George Romero had mathematical modeling in mind when he wrote this famous bit of dialogue for his zombie cult classic Dawn of the Dead. However, the laws of nature and nature’s God spare no one.
The survival of humanity and our demographic decline from living to undead is surprisingly simple to express mathematically. In theoretical epidemiology the original idea of predicting or tracking an infectious disease as it spread throughout the population was known as the Kermack–McKendrick theory. However, their findings were eventually simplified and are commonly credited as a basis for the SIR model used by most scientists and students today.
Many members of the Zombie Research Society have used the SIR model itself to explain the spread of disease; susceptible, infected, recovered. In fact, it’s the main reason we often refer to a zombie apocalypse as “inevitable” – the math simply isn’t on our side. However, a group of PhD students at the University of Sheffield have reinterpreted the “recovered” variable of that infamous equation in a way that could ultimately spell success for the entire human race!
The project, developed by maths PhD students at the University of Sheffield, has been showing the public how we can apply maths to a zombie apocalypse situation to explain how we understand the spread of disease in the real world.
The mathematicians used an SIR model to show how attempting to fight the zombies would lead to more people becoming infected and coming back as a zombie. Sending in the military was another option they considered but this lead to the same output.
The SIR model looks at people susceptible to a disease, those infected and those recovered. For example in the zombie model, humans are susceptible, the zombies are infected and the domesticated zombies are recovered.
Hiding from the zombies was the second best choice meaning humans could survive longer if they could not be found. The researchers showed the best method would be to domesticate the zombies, in real life this would be the equivalent of vaccination.
This new mathematical model took the unique approach of including domesticated zombies. While we’ve already seen this idea expressed in a number of popular films including Fido and Shaun of the Dead; it hasn’t really been applied to the SIR model until now. Apparently, this new curve has the potential to overtake “wild” zombies and somehow contribute to our global economic development. They’ve even produced a pretty cool video to explain their results!
The project simply broke down humanity’s chance of survival into four main categories; fight, hide, military, and domesticate. Obviously, we have more trust in the first three methods than the students of Sheffield. For example; slaughtered zombies don’t necessarily “rise up again” over and over. Fallen soldiers don’t always contribute to the zombie population. And a nice, secluded hiding spot can actually increase the human population, if you know what we mean.
Regardless, their project is a wonderful example of how we can apply math to the inevitable zombie apocalypse, help explain epidemiology, utilize statistical analysis, and demonstrate the spread of infectious diseases in real world situations. The very concept of redefining the old definition of “recovered” to include “domesticated” is certainly an interesting take on the classic SIR model. But we can’t really picture the undead manning a call center any time soon!
If you’d like to learn more about how these students redefined the scientific term “recovered” to mean “domesticated” simply visit the University of Sheffield website, or check out the video we’ve embedded below. Of course, if you’re old-school; you can always learn about the classic Kermack-McKendrick or SIR model of analyzing a transmitted infectious diseases by visiting the links above. It’s all worth your time, because what you don’t know can eat you!